I ordered the Reiff engine heater, they shipped same day..looking forward to putting it on and using aircraft once again during these very cold and clear winter days...only draws 100 watts so not costly to run..like a 100 watt light bulb...so will keep it plugged in all winter...

I ordered the Reiff engine heater, they shipped same day..looking forward to putting it on and using aircraft once again during these very cold and clear winter days...only draws 100 watts so not costly to run..like a 100 watt light bulb...so will keep it plugged in all winter...

Just ordered mine too.. Just decided it was a less expensive way to go then chance damage to engine with cold temps.

So now the discussion at hanger is: Leave it plugged in all the time or just night before flying...however I never know if I will fly because weather change so much overnight...and it was brought up that leaving it plugged in all the time contributes to moister condensation on inside of engine resulting in rust forming on cam and cylinder walls....guess there has been record of this happening on Lycomings etc....comments appreciated

Are you talking about your Rotax? Does the heater go on the oil reservoir or on the engine? To pre-warm the oil, it would need to go on the reservoir which would make the condensation issue moot since its not on the engine. If the heater is on the engine, I don't see the point of that. There's no oil in there and condensation would be a concern.

So now the discussion at hanger is: Leave it plugged in all the time or just night before flying...however I never know if I will fly because weather change so much overnight...and it was brought up that leaving it plugged in all the time contributes to moister condensation on inside of engine resulting in rust forming on cam and cylinder walls....guess there has been record of this happening on Lycomings etc....comments appreciated

Are a number of articles on the Reiff website that support leaving the system plugged in 100% of the time. The Aviation Consumer article specifically addresses condensation and corrosion.
From the Aviation Consumer, March 2007, pg. 23

Can't print the article due to their copyright, but you can buy a copy off their web site. Here are a few excerpts:

They instrumented a Continental 520 on a Bonanza that was equipped with our the Reiff Standard System. The preheat system was plugged in and they recorded internal crankcase temperature and %RH (relative humidity) data over a 7 day span. During that period ambient temps ranged from teens to 30F.

Results... The internal RH started at 60%RH at ambient temperature. After about 12 hrs of heating it stabilized at about 120F and 15%RH and it held pretty constant for 7 days.

"Clearly, a preheater seems to dry the engine out, not cause it to behave like a terrarium."

"While our experiment is far from definitive and doesn't consider all possible ambient conditions, it does seem to show that far from causing corrosion, an always-on preheater actually appears to benefit the engine."

Electric heaters are used for the purpose of preventing condensation in cabinets containing electrical and/or electronic equipment. My opinion is that electric heat will cause dryness, not dampness. Unvented propane or natural gas heaters WILL cause dampness because one of the byproducts of combustion is water.

on the other hand.........law of physics says you double the chemical reaction rate for every 10 deg. c. rise in temp. rusting is a chemical reaction.
i talked to reiff about this at osh a few years ago but as i remember you were still better off with the heat.anyone else talked to reiff about that aspect?

it is my very non professional opinion that plugged in all the time must keep things warmer and less condensation, consequentially less rust etc..plus being able to fly at drop of hat...thanks for all the help and comments..

OK Folks ….. I’m going to go out on a limb here regarding the corrosion issue and say heated or unheated, the corrosion issue would be minimal in the Rotax engine as installed on the RV-12. I may be all wet about this, but I feel the ideas mentioned thus far need to be narrowed to the Rotax engine specifically.

My reasoning is based on my belief that the Rotax oil system is a closed system …. in that, there is no direct venting on the Rotax crankcase directly to the atmosphere as opposed to a traditional aircraft engine, which vents directly to the crankcase of the engine. This is a BIG difference. Thus, it would appear to me that it would be very difficult to develop significant moisture deep inside the Rotax engine once the oil has been above 212 degrees for an extended period of time … because at that point, there is no moisture inside the engine and no direct path for atmospheric moisture into the crankcase via a crankcase vent tube as there is with a traditional engine. Because of the location of the Rotax oil tank in the RV-12, the oil lines between the oil tank and engine isolate the atmosphere presented to the oil tank from the vent line … thus preventing atmosphere from directly entering the Rotax crankcase because residual oil in the oil lines block the direct path for moisture to get inside the engine’s crankcase from the oil tank.

Of course, as with any standard aircraft engine, there is a path for moisture to get into the cylinders through open intake or exhaust valves. To my way of thinking, the potential corrosion areas would be any exposed cylinders themselves, the heads or tops of the pistons … as it would be for any standard aircraft engine. Seemingly, the majority of the internal engine components such as the crank, rods, cam, push rods, lifter/rocker arms, valve stems, and the clutch/gear reduction unit would, by in large, be spared from corrosion due to the lack of direct contact with the atmosphere.

As such, I suspect the use of a block and oil tank heater on the Rotax will be beneficial overall for starts in really cold weather without the worry of creating an atmosphere for corrosion developing deep inside the engine. For the Rotax, guessing turning on the heater the evening prior to a desired flight would be sufficient to minimize the moisture buildup inside the combustion chambers of those cylinders with open valves.

The above is just a theoretical guess on my part and not based on any conclusive testing. I would be very interested in hearing what others think about this. Perhaps one of the more experienced Rotax mechanics can offer some real world experience to the topic.

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